Agitating sap

[johnallin]

Pretty quiet around here lately...I've been reading but not much posting.
I did come across an interesting article in Maple News though about a project CDL and a Vermont producer have been working on where they're re-circulating and "agitating" sap. If i read it correctly, air is introduced and it looks like it either releases bad bacteria or introduces good...(all that is above my pay scale though)

So; in an effort to increase ratings - and have something to read at the end of the day - I thought I'd start a thread.

Anyone else try this? It seems like a simple enough process. I installed an H20 Innovation air injection/bubbler system last season in flue and syrup pans with good results and this has me thinking.

[fred]

Speaking of agitating....

Several producers have done this for the last 2 years. At this point they have almost figured out what works and what doesnt. At this years annual meeting cdl dealers had enough feed back through experiments with their set ups to create a commercial outfit to make it work well. They turned sour and buddy sap into a usable finished product. This will nearly eliminate the junk market when used properly

[johnallin]

Speaking of agitating....

Several producers have done this for the last 2 years. At this point they have almost figured out what works and what doesnt. At this years annual meeting cdl dealers had enough feed back through experiments with their set ups to create a commercial outfit to make it work well. They turned sour and buddy sap into a usable finished product. This will nearly eliminate the junk market when used properly

Nothing's more fun than agitating. Did I ever tell you how good my Leader Clear Press works??

Here's the link to one of the Maple News articles:
https://www.themaplenews.com/story/get-it-bubbling/258/

[DrTimPerkins]

This process (adding air to sap) works by reducing some of the off-flavor precursors and by allowing for the development of more strong flavors (by having more time elapse and/or by diluting and reboiling, similar to the metabolism off-flavor removal process). In the case of the VT sugarmaker (Bob White), they are very interested in developing a certain good flavor. In the case of the Cornell work and much of the work in Quebec, they are more interested in reducing/removing buddy (or sour) off-flavor. In both cases, there is a great deal more to learn, but progress is being made.

[johnallin]

I may pipe my air injection system into my sap tank.
I’d think a few minutes of that should add lots of oxygen.
It’s charcoal filtered air, so should not introduce any off flavor.

[minehart gap]

If I am recalling what I have read correctly, if you introduce air into the sap while the sap is cooking it may and usually does lighten the color and subsequent taste of the finished syrup but if you are to introduce that same air into the sap before it is processed it will both darken and embolden the flavor of the finished syrup.

So does that mean that at the end of the season one could in theory introduce air for the purpose of reducing off flavor and inadvertently darken the finished product but introduce air in the evaporator while cooking the sap and lighten it back with a more delicate flavor?

[johnallin]

Matt
I got the same impression. We definitely made lighter syrup this year with air injection but I think our taste wasn’t the same. It would seem that one may cancel the other?

[DrTimPerkins]

If I am recalling what I have read correctly, if you introduce air into the sap while the sap is cooking it may and usually does lighten the color and subsequent taste of the finished syrup but if you are to introduce that same air into the sap before it is processed it will both darken and embolden the flavor of the finished syrup.

Air injection into pans produces light syrup. Air injection into sap produces darker syrup. A little paradoxical isn't it. ;^)

So does that mean that at the end of the season one could in theory introduce air for the purpose of reducing off flavor and inadvertently darken the finished product but introduce air in the evaporator while cooking the sap and lighten it back with a more delicate flavor?

You might think so, but no. The reaction with air injection IN THE PANS is not a bleaching effect, but rather is a prevention or reduction of of color/flavor formation effect (I won't get into the chemical reasons, but it is largely due to a reduction in temperature resulting in a reduction in caramelization of invert).

The air injection INTO SAP effect is different. In this case you are:
1. volatilizing (reducing) off-flavor precursor compounds in the sap that result in poor flavor
2. enhancing formation of invert (higher temperature, more oxygen, longer time period) which increases color/flavor formation.
3. altering the biome of microbes in the sap.
4. increase the rate of biological and chemical reactions in sap leading to color/flavor development.

All of these factors INCREASE color/flavor development (and can, perhaps, decrease some off-flavor precursors), thus darker syrup is formed upon boiling. Essentially you are controlling the fermentation level in the sap. The danger is the possibility of turning your sap/syrup ropey.

Now if you used air injection in your pans to process aerated sap, you'd make lighter syrup, but it wouldn't be quite as light as if you had not aerated the sap. It would certainly be possible to vary the amount of air injection in the pans to be able to produce somewhat lighter or darker syrup according to your wishes (dial-a-grade syrup).

[Super Sapper]

One thing to watch would be increasing the temperature of your sap. The temperature of compressed air is usually increased going through the air compressor. This could be why it darkens the syrup.

[johnallin]

One thing to watch would be increasing the temperature of your sap. The temperature of compressed air is usually increased going through the air compressor. This could be why it darkens the syrup.

The H20 Air injection does not use an air compressor, rather a high volume air blower drawing through 3 charcoal filters. Sounds like a 747 Jet engine...